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Cthulhu uses a five-pin MX-style footprint and is intended for mechanical keyboard PCBs or hot-swap sockets that support five-pin switches. Boards designed only around a three-pin footprint should be checked before purchase because the two extra plastic locating pins require matching PCB clearance.
Factory lubricated across the confirmed 37g, 45g and 50g SKUs; no additional hand lubrication is required for basic installation or initial testing.
Cthulhu uses a 5-pin MX-style footprint, so the PCB or hot-swap socket must provide clearance for the two additional plastic locating pins. Check 3-pin-only boards before ordering instead of assuming every hot-swap keyboard accepts a 5-pin switch. Use the 10-switch pack for testing or replacements, while the 70-switch pack can cover many compact builds; count the actual switch positions and allow a few spares.
Use verified force, travel, mount and lubrication fields to see how this switch differs from nearby alternatives.
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SU LAB × HMX Cthulhu Linear SwitchCurrent
View product
|
HMX Fire Phoenix Linear SwitchView product |
OUTEMU Silent Peach V3 Linear SwitchView product |
|---|---|---|
| Type Linear | Type Linear | Type Linear |
| Operating force 45 gf | Operating force 37 gf | Operating force 40 |
| Bottom-out force 50 gf | Bottom-out force 42 gf | Bottom-out force 50 |
| Pre-travel 2 mm | Pre-travel 2 mm | Pre-travel 2 |
| Total travel 3.5 mm | Total travel 3.6 mm | Total travel 3.3 |
| Mount 5-pin | Mount 5-pin | Mount 5-pin |
| Factory lube Yes | Factory lube Yes | Factory lube Yes |
CRISP LINEAR
SU LAB × HMX Cthulhu is a factory-lubed linear with 2.0 mm pre-travel and 3.5 mm total travel.
Its intended direction is crisp and lively rather than silent or tactile; the keyboard build still affects the final sound.
Bottom line: A shorter-travel linear for buyers who want a lively response.
WEIGHT & CONSTRUCTION
Cthulhu uses an M1 modified POM stem, a 22mm extended spring, and factory lubrication across its listed weight options. Those construction details stay consistent while the 37g, 45g, and 50g choices change how much resistance the press presents.
That makes weight selection the practical decision: choose the resistance you want without changing the switch from its linear, 3.5mm-travel format.
What it means: Weight choice changes effort, not the basic linear format.
FIVE-PIN BUILD
Cthulhu uses a five-pin MX-style footprint. Confirm that the PCB and hot-swap socket accept the locating legs before selecting a build quantity.
Choose the weight after the fit check, then count the keyboard’s actual switch positions.
Build note: Confirm five-pin fit before ordering a full set.
WHO IT SUITS
Choose Cthulhu when you want a crisp, lively linear and can select the resistance that suits your hands.
Choose a quieter linear for noise-sensitive use, or choose a tactile switch when a distinct bump is the priority.
Decision note: Cthulhu is the lively, non-silent linear choice.
HMX Cthulhu is a linear MX-style mechanical keyboard switch designed by SU LAB and manufactured by HMX. It uses a five-pin PCB mount, a 22mm extended spring and factory lubrication. The keypress has no tactile bump or click mechanism, so the movement remains linear through the stroke.
The three Cthulhu versions share the same housing materials, stem material, travel and five-pin footprint but use different spring weights. The 37g option is the lightest, 45g is the balanced middle choice and default selection, and 50g provides the firmest resistance and bottom-out.
The 37g version is specified at 37g actuation and 42g bottom-out. The 45g version uses 45g actuation and 50g bottom-out. The 50g version uses 50g actuation and 56g bottom-out. All three retain approximately 2.0mm pre-travel and 3.5mm total travel.
Yes. The 37g, 45g and 50g versions are all factory-lubed switches. That makes the switch suitable for installation and testing without requiring hand lubrication before first use.
Cthulhu uses an M1 modified POM stem, a polycarbonate top housing and an HMX P7 bottom housing. Retailer descriptions characterize P7 as a high-fiberglass nylon formulation. The switch also uses a 22mm KOS single-stage extended spring across the confirmed force options.
It can be used with hot-swap keyboards whose PCB and sockets support a five-pin MX footprint. Some boards only provide a three-pin layout, so check the PCB before ordering rather than assuming every hot-swap keyboard accepts the two additional plastic locating pins on a five-pin switch.
Product and retailer descriptions consistently place Cthulhu on the loud, crisp and clacky side of linear switches. Treat that as a sound direction rather than a fixed measurement, because the case, plate, keycaps, foam, mounting system and desk surface can all change the finished keyboard acoustics.
A 10-switch pack is useful for testing, replacements or keeping spares. A 70-switch pack can cover many compact and 65% keyboards, but layouts vary. Count the actual switch positions on your board and allow a few spare switches before choosing the larger pack.